1. Field of the Invention
The present invention relates to a cassette drive assembly for a telephone answering device in which a single motor alternately drives only the outgoing announcement tape cassette or only the incoming message tape cassette, depending solely upon the direction of rotation of the motor.
The invention is covered by Disclosure Document No. 099,479 filed Apr. 13, 1981.
2. Description of the Prior Art
The use of magnetic tape cassettes is particularly desirable in a telephone answering device. Space is minimized, there is no problem of accidental tape spillage, and the cassettes are easy to handle and replace. Recorded incoming messages can be retained by simply substituting a new cassette for recording future messages.
The inventor's U.S. Pat. No. 4,118,602 shows a simplified mechanical control arrangement for a telephone answering device employing a reel-to-reel incoming message recording tape and a separate outgoing announcemnt loop. The mechanism employs two control arms connected by a lost motion linkage. Once control arm selects forward or rewind operation of the incoming message tape, and the other facilitates answer or playback mode selection.
In the inventor's copending U.S. patent application Ser. No. 211,241 filed Nov. 28, 1980, there is shown a related mechanical control arrangement for a telephone answering device in which magnetic tape cassettes are used for both the outgoing announcement and for recording incoming messages. This embodiment likewise employs two control arms, one for forward-rewind selection and the other for answer-playback mode control, but is configured to meet certain drive requirements unique to tape cassettes. For example, it includes a drive transfer assembly for separately driving the takeup spindle or the supply spindle of the incoming message tape cassette respectively during forward or rewind operation.
In both of the foregoing systems, a single motor continuously drives both the outgoing announcement tape loop and the incoming message record tape during the entire answering cycle. As a result, each time that a call is answered, either the entire outgoing announcement is recorded on the incoming message tape, or, even if recording is inhibited, the message tape advances a corresponding distance. This reduces the amount of space available for recording incoming messages, thereby reducing the number of calls that can be answered automatically before the tape supply is exhausted. An additional disadvantage is that when the recorded incoming messages are played back, the listening time is increased since between each recorded call the incoming message tape contains either a reproduction of the outgoing announcement or a blank space.
These problems could be eliminated by using separate motors alternately to drive the outgoing and incoming message tapes. Another approach is the use of an electromechanical clutch or drive transfer assembly to couple a single motor only to the outgoing announcement tape loop during the initial portion of the answering cycle and only to the incoming message tape during the remainder portion of the answering cycle. Such approaches are relatively costly, since they require either a second motor or additional electromechanical components. Moreover, such approaches do not readily lend themselves to incorporation with the simplified mechanical control arrangements presented in the above-mentioned U.S. Pat. No. 4,118,602 and application Ser. No. 211,241.
Thus it is an objective of the present invention to provide a simplified, single motor drive system for a telephone answering device in which only one or the other, but not both, of the outgoing announcement and incoming message recording tapes are driven at one time. Another objective is to provide such a system in which only the direction of rotation of the single motor determines which of the two tapes is driven. A further objective is to provide such a system for use with a telephone answering device utilizing magnetic tape cassettes and a simplified, two control arm, mechanical control arrangement.